I want to learn to speak Arabic, what is a good source?

My grandmother is from Syria and my dads whole side of the family speaks arabic. I hate not being able to understand them, or even just communicate with them, i feel as if i would be more 'accepted' if i could speak the language, and ive been wanting to for years and years. Im 17 years old, and VERY intersted in the culture. Should i use rosetta stone? how much will it cost? is it effective? and so on.....Please if you have used rosetta stone leave your feedback and your story...much appreciated